Do you stick to recipes when cooking/preparing food spontaneously?

Depends if it is something I'm familiar with. Temperature probe if I'm cooking joints of meat but otherwise I can normally tell if it is cooked okay.

Yes, I do because I am under the assumption that the ones that wrote it know better than I do.

Generally yes, unless I know a good substitute. Not like those people, "Hey, this recipe sucks. I used gluten free tortillas instead of rice, canned tuna instead of grilled beef, and grass from the lawn instead of peppers. Author should be ashamed."